Tray for use in a sorting machine

ABSTRACT

A tray for use in a sorting machine consists of a rectangular frame (17) which is covered with fabric (18). The frame (17) is pivotally suspended from two U-shaped rods (19) and is horizontal in the position of equilibrium. The frame (17) can be pivoted from the position of equilibrium to an inclined discharge position. During this, discharge (22, 25) or (23, 24) hit the fabric (18) and stretches it so that emptying of the contents of the tray takes place rapidly and effectively.

The invention concerns a tray of the type stated in the introductoryportion of claim 1.

The Danish Patent Specification 155 207 discloses a sorting machinecontaining a plurality of trays, which are moved in an endless path andcan be pivoted about a pivot axis by a selectively controllableactivation means for emptying the contents of the tray on a desiredunloading means.

EP-A1-022602 discloses a tray which together with a plurality of similartrays is suspended from a conveyor. These trays are used fortransporting lumps of dough. To avoid sticking of the dough lumps to thesubstrate, which is a cloth passed around some smooth rods, one of theserods is provided with an anti-slip material on the surface and isrotated evenly during transport, such that the cloth, on which the doughrests, is constantly displaced and such that the dough rolls in asagging part of the cloth.

The object of the invention is to provide an improved tray which may beused e.g. in the mentioned known sorting machine.

This object is achieved according to the invention in that the traystated in the opening paragraph is characterized by the features definedin the characterizing portion of claim 1.

Loading of the tray with parcels takes place in that the parcels falldown on the tray. The parcels then hit the fabric-covered frame whichmitigates the drop so that the parcels are protected against damage, andthe sorting machine operates with less noice than with the previouslyused trays.

When at least one of the two-armed levers of the tray is activated by anactivation means, known per se, in the sorting machine, the pivotedsuspension of the fabric-covered frame causes the frame to pivot fromthe horizontal position of equilibrium to an inclined discharge positionin the support, in which it is pivotally suspended in the two-armedlevers.

The support consists of the U-shaped rods on which discharge means aresecured, and which, in the inclined discharge position of the frame,engage and stretch the fabric on the frame so that the parcels arealmost thrown off or slide easily down from the tray.

The invention will be explained more fully below with reference to thedrawing, in which

FIG. 1 schematically shows one end of a sorting machine known from theDanish Patent 155 207, in which the tray known from said patent has beenreplaced by the tray of the invention,

FIG. 2 is a perspective view of the tray of the invention in ahorizontal position of equilibrium,

FIG. 3 is a lateral view of the tray from FIG. 1 and shows in brokenlines the same tray which has been pivoted from the horizontal positionof equilibrium to an inclined discharge position, and

FIG. 4 shows the right side of the tray in FIG. 3 from the end.

The sorting machine shown in FIG. 1 contains a plurality of trays whichare generally designated 1 and shown in more detail in FIG. 2. Thesetrays are pivotally suspended at both sides in pivots 2, 3 in the centerof their respective two-armed levers 4 and 5, respectively. The pivots2, 3 are secured to their respective ones between two chains 7 and 8driven in synchronism and by the same drive motor (not shown), saidchains being shown in broken lines in FIG. 1. The chains 6 and 7preferably consist of steel wires 8, 9, which are placed around a chainwheel at each end of the sorting machine.

Since only one end of the sorting machine is shown in the drawing, onlyone pair of chain wheels 10 and 11 is visible for each steel wire 8 and9, respectively.

Below the trays in both the upper and the lower run of the path, aplurality of stationary chutes 12 is placed at even intervals in amachine frame (not shown), in which a corresponding number of levers 14is secured, said levers being pivotable about a horizontal shaft 13.

The levers 14 can be caused to assume an activated state by means oftheir respective pneumatic cylinders 15, during which the associatedlever 14 is caused to engage a projection in the form of a wheel 16 onthe two-armed lever 4 or 5 of a tray 1. Consequently, the tray 1 inquestion is pivoted from the horizontal position of equilibrium to aninclined discharge position in which the contents of the tray 1 areemptied onto a chute 12 disposed below.

When the levers 14 are not activated, the trays 1 just pass unaffected.

Feeding to the sorting machine is affected from a feeding unit (notshown), which may be placed in any desired stationary position above theupper or lower run of the path, and the contents of the trays 1 areautomatically controlled for emptying into a chute 12 determined by anidentification code on each tray 1.

One of the trays 1 incorporated in the sorting machine is shown morefully in FIGS. 2, 3 and 4.

The tray 1 consists of a rectangular frame 17 which is covered withfabric 18 as shown in dotted line. The frame 17 is pivotally suspendedfrom a support 19, 20 in bearings or hinge joints 21. The support 19, 20consists of two U-shaped rods 19 and 20 whose upwardly free ends arepivotally journalled in the ends of the two-armed levers 4, 5, whichappears in particular from FIG. 2.

The horizontal portion from each of the U-shaped rods 19 and 20 mountsdischarge means in the form of other U-shaped rods 22, 23 and 24, 25,respectively.

As shown in particular in FIG. 3, these discharge means 22-25 aredisposed below the fabric 18. When the projection 16 of the tray 1 hitsa lever 14, whose pneumatic cylinder 15 has been activated, the tray 1is tilted from the horizontal position of equilibrium shown in solidline in FIG. 3 to the inclined discharge position shown in dotted linein FIG. 3.

During this movement the rods 22 and 25 of the discharge means hit theunderside of the fabric 18 and stretch the fabric as shown in dottedline in FIG. 3, so that the parcels (not shown) easily slide off thetray 1.

It is clear for reasons of symmetry that the tray 1 in FIG. 3 can alsobe emptied to the other side, during which the other rods 23 and 24 ofthe discharge means hit and stretch the fabric 18.

Further, in another type of sorting machine the trays might be suspendedfrom a single steel wire, and in that case the trays are rotated 90°about a vertical line. In this embodiment, the contents of the trayswill be emptied to one or the other side of the transport direction ofthe steel wire.

I claim:
 1. A tray (1), e.g. for use in a sorting machine of the typewherein articles or parcels are transported on a plurality of such trays(1), which are moved along in an endless path and are pivotable from ahorizontal position of equilibrium to an inclined discharge position bya selectively controllable activation means (14) for discharging thecontents of each tray (1) on to a desired unloading means (12), saidtray (1) consisting of a retangular frame (17) which is covered by afabric (18) or a similar material, which is suspended at both sides froma support in pivots (2, 3) in the centre of two-armed levers (4, 5),characterized in that the support consists of two U-shaped rods (19, 20)to which discharge means (22, 23 and 24, 25) are secured, said dischargemeans hitting and stretching the fabric (18) on the rectangular frame(17) when the tray is pivoted from the horizontal position ofequilibrium to the inclined discharge position to one or the other side.2. A tray according to claim 1, characterized in that at least one ofthe two-armed levers (4, 5) carries a projection, e.g. a wheel (16), andthat with a view to pivoting the tray (1) to the inclined dischargeposition an activation means (14) is moved into the travelling path ofthe wheel (16) to engage the wheel (16) during the passage thereof.